What is ObjectUtils.min in Java?

min() is a staticthe methods in Java that can be called without creating an object of the class. method of the ObjectUtils class that is used to get the minimum object from a list of objects. The types/classes of the objects should implement the Comparable interface that defines the way in which the objects are compared.

  • The method returns the lesser object if any objects are non null and unequal.

  • The method returns the first object if all objects are non null and equal.

  • The method returns the lesser of the non null objects if any of the comparables are null.

  • The method returns null if all the comparables are null.

How to import ObjectUtils

The definition of ObjectUtils can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file:

<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the ObjectUtils class as follows:

import org.apache.commons.lang3.ObjectUtils;

Syntax

public static <T extends Comparable<? super T>> T min(final T... values)

Parameters

  • final T... values: The list of comparable values.

Return value

This method returns the minimum value.

Code

import org.apache.commons.lang3.ObjectUtils;
import java.util.Arrays;
public class Main{
    static class Person implements Comparable<Person>{
        private int age;
        public Person(int age) {
            this.age = age;
        }
        @Override
        public int compareTo(Person p) {
            return this.age - p.age;
        }
        @Override
        public String toString() {
            return "Person{" +
                    "age=" + age +
                    '}';
        }
    }
    public static void main(String[] args) {
        Person[] persons = new Person[]{
                new Person(3),
                new Person(5),
                new Person(8),
                new Person(10),
                null
        };
        System.out.printf("ObjectUtils.min(%s) = %s", Arrays.toString(persons), ObjectUtils.min(persons));
    }
}

Output

The output of the code will be as follows:

ObjectUtils.min([Temp{a=3}, Temp{a=5}, Temp{a=8}, Temp{a=10}, null]) = Temp{a=3}

In the code above, we define a class Person that has age as its attribute. The class implements the Comparable interface and the compareTo() method is overridden with custom logic of comparison.

In line 28, an array of Person class objects is defined with different values for age.

In line 35, we get the person object with the minimum age using the ObjectUtils.min() method.

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